Masterdrives Vector how to improve deceleration time

I have to improve the stopping time of a big load of an axial helper motor 1PH7-167-2JF33-0BA3driven from a Masterdrive Vector6SE7031-0TE60-Z. I reduced the ramp down time (P464) and opened torque limit P498 (-200%) but during ramp down i can record a negative torque max -160%. The question is: does that torque is enough related the ramp down time i have set or there is another limit (ex. regenerative power but it is already @ 198%)?

Thanks in advance everyone for any suggestions

Regards